1. Field of the Invention
The present invention relates to an improved exchanger and a method for achieving heat transfer between solid particles contained or circulating in an enclosure and the external environment.
The present invention also relates to the use of the exchanger in the circulating loop of the solid particles in a circulating bed boiler.
2. Description of the Prior Art
The prior art devices are cumbersome and generally have, for equal volume, lower performances than those obtained by the device and process of the invention.
In U.S. Pat. No. 3,087,253, a device is proposed which requires a large exchange surface for there is no recirculation of the solid particles between the central enclosure and the rest of the device.
The prior art may be illustrated by the following patents: EP-A-0095427, EP-A-0006307, EP-A-0033713, EP-A-0093063, FR-A-2261497, FR-A-11 28881, GB-A-1577717, GB-A-1299264, GB-A-1248544, US-A-2842101, US-A-35650022, US-A-4404755, US-A-4538549, US-A-2759710, as well as by the article entitled "Les technologies de combustion en lit fluidise" by R. DUMON published by A.I.M. Association des Ingenieurs Electriciens from the Montefiore Institute, on the occasion of the eighth session of the international, modern electric power station study days, held at Liege Oct. 26-30, 1981.